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Author Topic: Global Dimming - The aerosol masking effect  (Read 13284 times)

Hefaistos

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Re: Global Dimming - The aerosol masking effect
« Reply #50 on: August 12, 2020, 11:00:26 PM »
... Why would you use model reanalysis numbers to base the discussion on when real world physical temperature measurements are available (if you can wait a few days for the collation for monthly figures to be published)?
...

You obviously want to use data of the highest quality in different respects. Satellite data are considered to be higher quality than 'physical' data.

First, because you cover the entire globe in a more or less equally weighted grid. Physical data is only measured at certain spots, often near populated areas. We have very good coverage where many people live, but very little coverage where no people live. SH has e.g. very few measuring points compared to NH. Oceans in SH have very few points.

Secondly, also physical data has issues. Measuring points are moved. The urban heat island is a persistent issue that is not easily resolved. Measuring points are influenced by urban crawl.

Thirdly, if you want to track aerosol masking effects, the more relevant data are those that relate to the amount of heat energy in the atmosphere, i.e. sat data.

All reanalyses are built to a higher or lesser degree on sat data.

As regards the quality issue with NCEP it seems to be a model related temporary problem. Moyhu writes: "Although I noted doubts about NCEP/NCAR's recent results, the pattern of anomalies was qualitatively similar to that of TempLS."
https://moyhu.blogspot.com/2020/08/july-global-surface-templs-down-0039.html

You can check for yourself that this was a temporary issue on the page provided by Karsten Hausten,
http://www.karstenhaustein.com/climate.php
If you scroll to the very bottom of that page, you can compare the monthly means (CFSR-GFS, NCEP reanalysis, GISS temperature). You can follow the issues with NCEP , they are clearly noticeable since April of 2020.

And, finally, to come back on topic, there is still no signal at all to be seen from the diminished aerosols due to corona lockdowns. My conclusion is that there might be such signals on a regional level, but we will have to wait for the researchers to dig it out.

Moyhu btw provides a really nice zoomable trackball Earth temperature presentation, built on a mix of physical data and sat data:
https://moyhu.blogspot.com/p/blog-page_24.html

Example: If you zoom in on China you would expect to be able to see some lockdown effect on temperatures in e.g. April and May this year, but April was actually a cold month in China. May was warm, but not exceptionally so.
« Last Edit: August 12, 2020, 11:05:49 PM by Hefaistos »

glennbuck

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Re: Global Dimming - The aerosol masking effect
« Reply #51 on: August 16, 2020, 01:36:15 PM »
According to our regional analysis, Europe, Asia, the Caribbean region, and the Gulf of Mexico had their warmest January–July since regional records began in 1910. Europe had a year-to-date temperature departure of +2.10°C (+3.78°F), marking the first time the January–July temperature departure surpassed the 2.0°C (3.6°F) mark on record. This value surpassed the previous record set in 2014 by +0.12°C (+0.22°F). Europe's five warmest January–Julys on record have occurred since 2014.

For Asia, the year-to-date temperature departure of +2.57°C (+4.63°F) surpassed the now second warmest January–July set in 2016 by +0.48°C (0.86°F). Only January–July of 2016 and 2020 have a temperature departure surpassing 2.0°C (3.6°F).

https://www.ncdc.noaa.gov/sotc/global/202007

glennbuck

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Re: Global Dimming - The aerosol masking effect
« Reply #52 on: August 20, 2020, 11:43:22 PM »
The very persistent "warmth" (up to 5°C relative to average) across northern Siberia up to July this year.

Arctic Air Temperature rank per month and Arctic air temperature anomaly for Jan-July. Air temperature in March was lowest since 2004, April was 6th highest and May 1st highest on record, June 2nd highest and July 1st highest.

This years record Air temps seem to of happened for peak seasons melt, May, June, July and probably August when that data comes in. Where as 2016 has 6 months of record air temperatures but in Jan, Feb, March and Sep, Oct and Nov. The 2019 season had 2,3,4,1 highest air temps in May, June, July, August. The 2019/2020 season seem to be entering a new Paradigm for the Arctic.

Is this starting to form a pattern from reduced Aerosol masking effect/global dimming from the Lockdown's and reduced industrial output maybe. Russia has a very large Aerosol masking effect from Oil and Gas production.

https://www.scientistswarning.org/2020/06/04/dimming-dilemma/

According to this Geophysical Research Letters study, “we show how cleaning up aerosols, predominantly sulfate, may add an additional half a degree (0.5°C) of global warming, with impacts that strengthen those from greenhouse gas warming.” Most scientists, journalists and researchers speaking on this say the amount of warming from dimming given in the most widely cited and published estimates is between 0.25 and 0.5°C. Various other estimates discuss that between 0.25-1.1°C of warming MIGHT BE possible. Studies do vary widely. There is no one answer. But the most common answer given is 0.5°C. This is also given in the AR5, the latest IPCC reporting on this, which also gives 0.5°C.
« Last Edit: August 21, 2020, 06:51:16 AM by glennbuck »

kassy

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Re: Global Dimming - The aerosol masking effect
« Reply #53 on: August 21, 2020, 08:05:23 PM »
I think that is all related to the ongoing YOY deterioration and not masking.

One way to check some part of it is to find russian production and see if it changed in any way.
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kassy

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Re: Global Dimming - The aerosol masking effect
« Reply #54 on: August 25, 2020, 01:02:19 PM »
Glenn, how does this relate to global dimming?
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kassy

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Re: Global Dimming - The aerosol masking effect
« Reply #55 on: August 25, 2020, 10:23:21 PM »
The questionmark is the problem. You could post it here if you know it is topical or you have some good reason to suspect it is (and then you tell us why in the post etc).

This is related to large scale atmospheric patterns (and thus to AGW in general). The aerosol masking effect is more local to the pollution sources so it´s not involved here.
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glennbuck

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Re: Global Dimming - The aerosol masking effect
« Reply #56 on: August 26, 2020, 12:31:14 AM »
The question mark is the problem. You could post it here if you know it is topical or you have some good reason to suspect it is (and then you tell us why in the post etc).

This is related to large scale atmospheric patterns (and thus to AGW in general). The aerosol masking effect is more local to the pollution sources so it´s not involved here.

Oh ok this thread is not about the reduction in aerosol masking effect from industrial production
from the lockdowns increasing temperatures in the short term, which would require evidence of short term temperature increases like i have posted.

I will delete the temperature increases in the last 4 months in the Arctic, as it is not relevant to this thread on reduction of aerosol masking effects in the increase in short term temperatures rising, from global dimming being reduced locally and globally causing an increase in regional and global temperatures in the short-term involving global dimming and the aerosol masking effect.
« Last Edit: August 26, 2020, 01:00:07 AM by glennbuck »

kassy

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Re: Global Dimming - The aerosol masking effect
« Reply #57 on: August 27, 2020, 09:42:28 AM »
I moved the pole anomalies over to this thread:

https://forum.arctic-sea-ice.net/index.php/topic,445.0.html
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FrostKing70

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Re: Global Dimming - The aerosol masking effect
« Reply #58 on: November 02, 2023, 05:00:08 PM »
Interesting, if alarming read!

Experts underestimate how fast Earth is warming, top climate scientist says in new study


"Legendary climate scientist James Hansen, in a new study published Thursday, predicts that the Earth's temperature rise will accelerate in the upcoming decades and will reach 2 degrees Celsius above pre-industrial temperatures by 2050. This is significantly more than the most common current estimates from groups such as the Intergovernmental Panel on Climate Change (IPCC), typically considered the planet's gold standard for climate forecasts.

According to Hansen's new study, the revised prediction is due to previous underestimations of the effects of greenhouse gases on the atmosphere, along with the effects of aerosols, which have acted to mask some of global warming."

https://www.usatoday.com/story/news/weather/2023/11/02/global-warming-to-accelerate-faster-than-expected-james-hansen-says

Edit: Above link doesn't seem to work!  Attempt 2:

https://www.usatoday.com/story/news/weather/2023/11/02/global-warming-to-accelerate-faster-than-expected-james-hansen-says/71410876007/

kassy

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Re: Global Dimming - The aerosol masking effect
« Reply #59 on: November 02, 2023, 05:19:12 PM »
Important paper.

Also discussed here:

Hansen's  Pipeline  paper is published today.
https://academic.oup.com/oocc/article/3/1/kgad008/7335889?searchresult=1

snip

Hansen's own comments are at
https://www.columbia.edu/~jeh1/mailings/2023/HomePlanet.2023.10.27.pdf

Jump to the original for the full post and another one below that.
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